NIEHS is leading a National Institutes of Health (NIH) long term study looking at the potential health effects of the oil spill in various responder populations. During FY 2012,the GuLF STUDY (Gulf Long-term Follow-Up Study) continued its recruitment efforts. As of September 5, 2012, the GuLF STUDY has completed over 28,244 telephone interviews and over 6,747 in-person visits where biospecimens are collected. Biospecimens are banked in a long-term storage facility using liquid nitrogen where appropriate. NIEHS investigators are actively recruiting study participants into the GuLF STUDY. The study began recruiting Spanish-speaking and Vietnamese-speaking participants in summer 2012. dditionally, NIEHS investigators are working to obtain all of the available environmental and occupational exposure monitoring data in order to perform an accurate exposure assessment on the study population. Ongoing statistical modeling will lead to the development of cleanup-task exposure matirices that will will allow assignment of exposure estimates for volatile compounds and other exposures related to oilspill cleanup. A substudy assessing current exposures to volatile compounds and metals will begin collecting blood samples and environmental monitoring data in September 2012. Approaches and preliminary results from exposure characterization efforts were presented at several international meetings.